Overfill prevention valve

ABSTRACT

An overfill valve associated with a drop tube segment fluidly connected to a fluid reservoir is described. The overfill valve includes a valve body positioned within the drop tube segment and a non-contact valve actuator positioned exterior to the drop tube segment and operable to actuate the valve body from an open position to a closed position without requiring any physical penetration through the wall of the drop tube segment. The non-contact valve actuator has a first position in which the non-contact valve actuator does not actuate the valve body from the open position to the closed position in a second position, achieved when the liquid reservoir reaches a predetermined level approaching the capacity of the liquid reservoir, the non-contact valve actuator actuating the valve body from the open position to the closed position when the non-contact valve actuator obtains the second position.

This application is a continuation of U.S. application Ser. No. 16/429,809, filed Jun. 3, 2019, which is a continuation of U.S. application Ser. No. 14/026,308, filed Sep. 13, 2013, which claims priority under 35 U.S.C. 119(e) of U.S. Provisional Patent Application Ser. No. 61/701,347 filed on Sep. 14, 2012 and U.S. Provisional Patent Application Ser. No. 61/801,681 filed on Mar. 15, 2013, all of which are entitled Overfill Prevention Valve, the entire disclosures of which are hereby incorporated by reference herein.

BACKGROUND

The present disclosure relates to drop tube segments and, more particularly, to drop tube segments providing access to a liquid reservoir while controlling the flow of liquid into the reservoir to prevent overfilling of the same.

Underground storage tanks are routinely utilized to store fuels such as gasoline, diesel fuel, ethanol, etc. for later dispensing to vehicles through fuel dispensers. The underground storage tank contains an inlet through which fuel is provided to the underground storage tank, typically by a tanker truck. A plurality of fuel dispensers are also fluidly connected to the underground storage tank and are utilized to provide the fuel contained therein to, e.g., passenger vehicles.

Typically, a riser pipe extends upwardly from the underground storage tank to a fill connection point contained within a sump at the fueling station. Within the riser pipe, a drop tube extends downwardly into the volume of the underground storage tank.

The drop tube extends toward the bottom of the underground storage tank so that the outlet end of the drop tube is covered by the motor fuel contained in the underground storage tank. Therefore, the drop tube is not in fluid communication with the fuel vapor contained in the ullage area of the underground storage tank. However, the overfill prevention valve is typically positioned much closer to the top of the underground storage tank and is therefore typically in fluid communication with the vapor contained in the ullage area of the underground storage tank.

When filling an underground storage tank, the operator of a tanker truck must be careful not to overfill the underground storage tank. To this end, an overfill prevention valve may be utilized to prevent overfilling of the underground storage tank. For example, an overfill prevention valve may utilize a float which is buoyant on a surface of a quantity of motor fuel and which is connected by a linkage to a valve positioned within a segment of a drop tube connecting a fill point to the underground storage tank. The linkage extends through the wall of the drop tube so that it can mechanically connect the float, which is outside of the drop tube, and the valve body, which is inside the drop tube.

Because the overfill prevention valves of prior art devices include a mechanical linkage connecting a float positioned on the exterior of the drop tube with a valve body positioned on the interior of the drop tube, the wall of the drop tube segment containing the overfill prevention valve must be physically penetrated by the linkage to allow for such a connection. This physical penetration of the wall of the drop tube segment containing the overfill prevention valve creates a leak point where vapor contained in the ullage space of the underground storage tank can enter into the drop tube. It is desirable to prevent vapor contained in the ullage space of the underground storage tank from entering into the interior of the drop tube where it could potentially be vented to the atmosphere.

SUMMARY

The present disclosure provides an overfill valve associated with a drop tube segment including a valve body positioned within the drop tube segment and a non-contact valve actuator positioned exterior to the drop tube segment and operable to actuate the valve body from an open position to a closed position without requiring any physical penetration through the wall of the drop tube segment. The non-contact valve actuator has a first position in which the non-contact valve actuator does not actuate the valve body from the open position to the closed position and a second position, achieved when the liquid reservoir reaches a predetermined level approaching the capacity of the liquid reservoir, the non-contact valve actuator actuating the valve body from the open position to a closed position when the non-contact valve actuator attains the second position.

In one form thereof, the present disclosure provides an overfill prevention valve including a conduit having a first end and a second end, a conduit wall spanning the first end of the conduit and the second end of the conduit, the conduit wall defining a conduit wall interior surface and a conduit wall exterior surface, the conduit wall interior surface defining a fluid path through the conduit from the first end of the conduit to the second end of the conduit; a valve body moveably positioned in the fluid passage of the conduit, the valve body moveable from an open position to a closed position; and a non-contact valve actuator moveable relative to the valve body and positioned outside of the conduit, the conduit wall interposed between the non-contact valve actuator and the fluid path, the non-contact valve actuator operable to actuate the valve body from the open position toward the closed position without physically penetrating the conduit wall, the non-contact valve actuator having a first position in which the non-contact valve actuator does not actuate the valve body from the open position toward the closed position and a second position in which the non-contact valve actuator actuates the valve body from the open position toward the closed position. In the open position, the valve body allows fluid to pass through the fluid path defined by the conduit at an expected fill rate. In certain embodiments, in the closed position, the valve body precludes flow through the fluid path defined by the conduit at the expected fill rate but may allow fluids to pass through the fluid path defined by the conduit at a decreased flow rate to allow drainage from a quantity of fluid positioned upstream of the valve body in the drop tube. In certain alternative embodiments, the valve body may comprise a butterfly valve, a flapper valve, and/or a poppet valve.

In alternative forms of the present disclosure, the overfill prevention valve may include a closure stop movably positioned in the fluid path of the conduit, the closure stop having a leak position and a non-leak position, with the valve body in the closed position and the closure stop in a leak position, a quantity of fluid is able to leak past the valve body. In one form of the present disclosure, the closure stop may take the form of a stop that prevents the valve body from fully seating against the associated valve. In alternative forms of the present disclosure, the closure stop may take the form of a secondary valve, such as poppet valve or flapper valve that opens to allow leakage past valve body in its closed position.

In certain alternative embodiments, the non-contact valve actuator may be operable to actuate the closure stop from the leak position to the non-leak position without physically penetrating the conduit wall, the non-contact valve actuator of this form of the disclosure having a third position in which the non-contact valve actuator actuates the closure stop from the leak position to the non-leak position, the non-contact valve actuator of this form of the present disclosure not actuating the closure stop from the leak position to the non-leak position in the first position and the second position.

In one form of the present disclosure, the non-contact valve actuator may comprise a float having a specific gravity less than about 0.7 so that the float is buoyant on a surface of a quantity of motor fuel, which typically has a specific gravity in the range of 0.72 to 0.89.

In certain forms of the present disclosure, the non-contact valve actuator may include an actuator magnet producing a magnetic field acting to urge the valve body from the open position toward the closed position when the non-contact valve actuator is positioned in the second position. In alternative forms of the present disclosure, a valve body magnet may be associated with the valve body so that the magnetic field produced by the actuator magnet acts on the valve body magnet to urge the valve body from the open position toward the closed position. Alternative forms of the present disclosure contemplate a magnetic repulsion between the non-contact valve actuator and the valve body to urge the valve body from the open position toward the closed position. Further alternative forms of the present disclosure contemplate a magnetic attraction between the non-contact valve actuator and the valve body to urge the valve body from the open position toward the closed position.

Valve bodies of the present disclosure may take the form of, e.g., butterfly valves or flapper valves.

In alternative forms of the present disclosure, a deflector plate may be provided upstream of the valve body, with the deflector plate sized and positioned to prevent a quantity of fluid flowing through the conduit from contacting the valve body when the valve body maintains the closed position.

In alternative forms of the present disclosure, the non-contact valve actuator may comprise a first float moveable from the first position to the second position, the first float operable to actuate the valve body from the open position toward the closed position when the first float achieves the second position, the non-contact valve actuator further comprising a second float moveable relative to the first float from a rest position to the third position, the second float operable to actuate the closure stop from the leak position to the non-leak position when the second float achieves the third position.

In certain forms of the present disclosure, the non-contact valve actuator may include a closure stop actuator magnet producing a magnetic field acting to urge the closure stop from the leak position to the non-leak position when the non-contact valve actuator is positioned in the third position. In alternative forms of the present disclosure, a closure stop magnet may be associated with the closure stop so that the magnetic field produced by the closure stop actuator magnet acts on the closure stop magnet to urge the closure stop from the leak position to the non-leak position. Alternative forms of the present disclosure contemplate a magnetic repulsion between the non-contact valve actuator and the closure stop to urge the closure stop from the leak position to the non-leak position. Further alternative forms of the present disclosure contemplate a magnetic attraction between the non-contact valve actuator and the closure stop to urge the closure stop from the leak position to the non-leak position.

In certain embodiments of the present disclosure, the closure stop may comprise a stop cam rotatably connected to the conduit wall, the stop cam supporting the valve body above its valve seat in the leak position, the stop cam allowing the valve body to fully engage its associated valve seat when the closure stop maintains the non-leak position.

In alternative forms of the present disclosure, the valve body may include a poppet valve, a poppet valve port, a poppet valve seat and a spring biasing the poppet valve into engagement with the poppet valve seat to close the poppet valve port, so that with the valve body in the closed position and the closure stop in the leak position, the closure stop actuates the poppet valve against a biasing force of the spring to space the poppet valve from the poppet valve seat and place the poppet valve port in fluid communication with the fluid path.

In certain forms thereof, the overfill prevention valve of the present disclosure can be utilized in combination with an underground storage tank and a drop tube extending into the underground storage tank, the overfill prevention valve forming a part of the drop tube, the drop tube in fluid communication with the underground storage tank so that fluid passing through the drop tube fills the underground storage tank.

In another form thereof, the present disclosure provides an overfill prevention valve including a conduit having a first end and a second end, a conduit wall spanning the first end of the conduit and the second end of the conduit, the conduit wall defining a conduit wall interior surface and a conduit wall exterior surface, the conduit wall interior surface defining a fluid path through the conduit from the first end of the conduit to the second end of the conduit; a valve body moveably positioned in the fluid path of the conduit, the valve body moveable from an open position to a closed position; and a valve actuator means for actuating the valve body from the open position toward the closed position while the valve actuator means is positioned outside of the fluid path of the conduit and without physically penetrating the wall. In alternative forms of the present disclosure, the valve actuator means may comprise a means for generating a magnet field for actuating the valve body from the open position toward the closed position. Further, the valve actuator means may comprise a float having a specific gravity of less than 0.7 so that the float is buoyant on a surface of a quantity of motor fuel, which typically has a specific gravity in the range of 0.72 to 0.89. In alternative forms of the present disclosure, the overfill prevention valve may further include leak means for selectively allowing a quantity of fluid to leak past the valve body when the valve body is in the closed position and a leak actuator means for actuating the leak means from a leak position in which the leak means allows the quantity of fluid to leak past the valve body to a non-leak position in which the leak means does not allow the quantity of fluid to leak past the valve body.

In yet another form thereof, the present disclosure provides an overfill prevention valve including a conduit having a first end and a second end, a conduit wall spanning the first end of the conduit and the second end of the conduit, the conduit wall defining a conduit wall interior surface and a conduit wall exterior surface, the conduit wall interior surface defining a fluid path through the conduit from the first end of the conduit to the second end of the conduit; a valve body moveably positioned in the fluid path of the conduit, the valve body moveable from an open position to a closed position; and a magnetic valve actuator moveable relative to the valve body and positioned outside of the conduit, the conduit wall interposed between the magnetic valve actuator and the fluid path, the magnetic valve actuator operable to actuate the valve body from the open position toward the closed position without physically penetrating the wall, the magnetic valve actuator having a first position in which the magnetic valve actuator does not actuate the valve body from the open position toward the closed position and a second position in which the magnetic valve actuator actuates the valve body from the open position toward the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features of the disclosure, and the manner of attaining them, will become more apparent and will be better understood by reference to the following description of embodiments of the disclosure taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a representation of a fueling station showing a tanker truck filling an underground storage tank;

FIG. 2 is a perspective view of a drop tube segment in accordance with the present disclosure;

FIG. 3 is a plan view of the drop tube segment of FIG. 2 ;

FIG. 4 is a cross-sectional view of the drop tube segment of FIG. 2 ;

FIG. 5 is a cross-sectional view of the drop tube segment of FIG. 2 illustrating actuation of the valve body from an open position to a closed position;

FIG. 6 is a cross-sectional view of the drop tube segment of FIG. 2 illustrating the valve body in a closed position and the closure stop in a leak position;

FIG. 7 is a cross-sectional view of the drop tube segment of FIG. 2 illustrating movement of the closure stop from the leak position to the non-leak position;

FIG. 8 is an illustration of an alternative embodiment drop tube segment utilizing a magnetic attraction to actuate the valve body from an open position to a closed position;

FIG. 9 is a cross-sectional view of an alternative embodiment drop tube segment utilizing a flapper valve;

FIG. 10 is a cross-sectional view of the drop tube segment of FIG. 9 illustrating actuation of the flapper valve from an open position toward a closed position;

FIG. 11 is a cross-sectional view of the drop tube segment of FIG. 9 illustrating the valve body in the closed position and the closure stop in the leak position;

FIG. 12 is a cross-sectional view of the drop tube segment of FIG. 9 illustrating the valve body in the closed position and the closure stop in the non-leak position;

FIG. 13 is a top plan view of the drop tube segment of FIG. 9 ;

FIG. 14 is a perspective, exploded view of a further alternative embodiment drop tube segment;

FIG. 15 is a cross-sectional view of the drop tube segment of FIG. 14 ;

FIG. 16 is a cross-sectional view of the drop tube segment of FIG. 14 illustrating actuation of the valve body from the open position toward the closed position;

FIG. 17 is a cross-sectional view of the drop tube segment of FIG. 14 illustrating the valve body in the closed position and the closure stop in a leak position;

FIG. 18 is a cross-sectional view illustrating the drop tube segment of FIG. 14 with the valve body in the closed position and the closure stop in the non-leak position;

FIG. 19 is a top plan view of an alternative embodiment drop tube segment of the present disclosure;

FIG. 19 a is a radial elevational view of the drop tube segment illustrated in FIG. 19 ;

FIG. 20 is a sectional view thereof taken along line A-A of FIG. 19 ;

FIGS. 21, 23, 25, 27, 29 and 31 are all partial, radial elevational views of the drop tube illustrated in FIG. 19 , illustrating various stages of actuation of the associated valve structure;

FIGS. 22, 24, 26, 28, 30 and 32 are all sectional views of the drop tube segment illustrated in FIG. 19 , taken along line A-A of FIG. 19 , illustrating various stages of actuation of the associated valve structure;

FIG. 32 a is a radial elevational view of an alternative embodiment drop tube segment of the present disclosure;

FIGS. 33, 34 a, 36, 37 a, and 38 a are all sectional views of the drop tube segment illustrated in FIG. 32 a , taken along line D-D of FIG. 32 a;

FIGS. 34, 35, 37, 38, 39, 40, 41 and 42 are all sectional views taken along the plane of the page of FIG. 32 a;

FIG. 43 is a top plan view of an alternative embodiment drop tube segment of the present disclosure;

FIG. 43 a is a radial elevational view of the drop tube segment illustrated in FIG. 43 ;

FIGS. 44, 45, 46, 47, 48, 49 and 50 are all sectional views of the drop tube segment illustrated in FIG. 43 , taken along line A-A of FIG. 43 ;

FIG. 47 a is an orthogonal cross-sectional view of FIG. 47 ;

FIG. 48 a is an orthogonal cross-sectional view of FIG. 48 ;

FIG. 49 a is an orthogonal cross-sectional view of FIG. 49 ;

FIG. 51 is an elevational view of a valve actuator of the present disclosure;

FIG. 52 is a plan view of the actuator of FIG. 51 ;

FIG. 53 is an alternative elevational view of the actuator of FIG. 51 ;

FIGS. 54-56 are perspective views of elements of the actuator of FIGS. 51-53 ;

FIG. 57 is a radial elevational view of a drop tube and drop tube adaptor of the present disclosure;

FIG. 58 is a cross-sectional view of the drop tube and the drop tube adaptor illustrated FIG. 57 ; and

FIG. 59 is a perspective view of the drop tube adaptor and drop tube illustrated in FIGS. 57 and 58 .

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the disclosure and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

FIG. 4 illustrates drop tube segment 20 in accordance with an exemplary embodiment of the present disclosure. Drop tube segment 20 includes conduit 22 spanning first end 24 and second end 26 of conduit 22. Conduit wall 28 defines conduit wall interior surface 32 which defines a fluid path through conduit 22 from first end 24 to second end 26. Valve body 34 is moveably positioned in the fluid path of conduit 22 and moveable from the open position illustrated in FIG. 4 to a closed position such as the one illustrated in FIG. 6 . Non-contact valve actuator 36 is moveable relative to valve body 34 and positioned outside of conduit 22, with conduit wall 28 interposed between non-contact valve actuator 36 and the fluid path defined by conduit wall interior surface 32. Non-contact valve actuator 36 is operable to actuate valve body 34 from the open position illustrated in FIG. 4 to a closed position such as the one illustrated in FIG. 6 without physically penetrating conduit wall 28. Operation of non-contact valve actuator 36 will be further described herein below.

FIG. 1 illustrates an exemplary utilization of drop tube segment 20 in the context of a fueling station. As illustrated in FIG. 1 , a fueling station may include underground storage tank 94 having riser pipe 100 extending upwardly therefrom and drop tube 98 extending through riser pipe 100 and into the storage space of underground storage tank 94. Tanker truck 102 can be fluidly connected to underground storage tank 94 by fill hose 104 so that the contents of tanker truck 102 can be deposited in underground storage tank 94. Drop tube segment 20 of the present disclosure can be utilized as described in detail below to limit the amount of fuel deposited by tanker truck 102 into underground storage tank 94. The contents of underground storage tank 94 can then be accessed by fuel dispenser 106 for dispensing to end users in, e.g., passenger vehicles and the like.

The remainder of this detailed description will describe use of the overfill prevention valve of the present disclosure with respect to a fueling station; however, use of the drop tube segments of the present disclosure are not limited to fueling station installations. The overfill prevention valve of the present disclosure is generally useable in connection with any fluid reservoir into which a drop tube extends.

Referring to FIG. 6 , valve body 34 is illustrated in a closed position in which a small amount of flow can pass valve body 34. When valve body 34 maintains the open position illustrated in FIG. 4 , conduit 22 is sufficiently open to allow passage of fuel at a normal fill rate. For applications in standard configurations this fill rate is generally in the range of 300-500 gallons per minute (gpm). In certain embodiments, the maximum rated flow past valve body 34 in its open position is 400-450 gpm. In alternative configurations, the flow rate will be about 370 gpm. In applications with remote filling capability, the standard flow rate may be as low as 25 gpm. These flow rates are applicable to all of the embodiments described in this document. With valve body 34 in the open position as illustrated in FIG. 4 , the maximum fill rate is accommodated by conduit 22. In the closed position illustrated in FIG. 6 , the maximum fill rate is not allowed and, if filling at such a rate were to continue, the portion of drop tube 98 upstream of valve body 34 would fill with a column of fluid. The actuation mechanism which causes valve body 34 to move from the open position illustrated in FIG. 4 to the closed position illustrated in FIG. 6 (which will be described in more detail hereinbelow) causes rapid closing of valve body 34, causing the fluid column upstream of valve body 34 to produce a line shock which will cause fill hose 104 to jump, which is typically referred to as “hose kick” in the fueling industry. Hose kick alerts the driver to close the delivery valve on the delivery truck and discontinue filling the fuel tank.

With valve body 34 closed as illustrated in FIG. 6 , but with closure stop 50 preventing full seating of valve body 34 against its valve seat, the column of fuel upstream of valve body 34 in drop tube 98 will slowly leak past valve body 34, allowing fill hose 104 to drain so that it can be properly disconnected from the fill port connected to underground storage tank 94. Valve body 34 is said to be in a “closed” position when it disallows passage of fluid at the maximum fill rate associated with underground storage tank 94. In such a position, a small amount of flow past valve body 34 may be allowed as described above. In embodiments of the present disclosure, the “leak” flow rate will be about 10% (or less) of the maximum rated flow discussed above. For example, a valve having maximum rated flow of 400 gpm will have a leak flow rate of 40 gpm or less. Any time this document refers to a leak flow rate or a leak condition, such reference is to a flow rate of about 10% or less of the maximum rated flow of the conduit. Even with the “leak” flow eliminated, as described herein with respect to the various embodiments, a “drain” rate of about 2% or less of the maximum flow rate may be allowed to pass the valve bodies of certain embodiments of the present disclosure. In alternative embodiments, the “drain” rate may be about 0.66 GPM or less. Similarly, any time a “drain” flow rate is mentioned in this document, it signifies a flow rate of about 2% or less of the maximum flow rate. In alternative embodiments of the present disclosure, each and every embodiment disclosed herein may incorporate a drain flow rate, although such incorporation is not necessary with respect to all embodiment disclosed herein.

Referring to FIGS. 2-7 , the functional details of an exemplary overflow prevention valve in accordance with the present disclosure will now be described. Referring to FIG. 4 , valve body 34 is pivotally connected relative to drop tube segment 20. In an exemplary embodiment, valve body 34 may be pivotally connected by a rod connected to conduit wall interior surface 32 and spanning conduit 22 of drop tube segment 20. In the embodiment illustrated in FIGS. 2-7 , valve body 34 comprises a butterfly valve having valve halves 108, 110 pivotally connected relative to drop tube segment 20. Valve halves 108, 110 can be biased into the open position illustrated in FIG. 4 , e.g., by a torsion spring. Arm 112 extends from valve half 108 and carries valve body magnet 44. With underground storage tank 94 filled to less than its capacity, tanker truck 102 can be utilized to provide additional motor fuel to underground storage tank 94. As underground storage tank 94 nears capacity, non-contact valve actuator 36 will actuate valve body 34 from the open position illustrated in FIG. 4 toward the closed position illustrated in FIG. 6 .

Drop tube segment 20 includes non-contact valve actuator 36 positioned about conduit wall exterior surface 30, with conduit wall 28 interposed between and physically separating non-contact valve actuator 36 from valve body 34. As will be described hereinbelow, non-contact valve actuator 36 is capable of actuating valve body 34 from the open position illustrated in FIG. 4 to a closed position such as the one illustrated in FIG. 6 without physically penetrating conduit wall 28. In the exemplary embodiment illustrated in FIGS. 2-7 , non-contact valve actuator 36 comprises a hollow cylinder sized to fit about and surround conduit wall exterior surface 30. Non-contact valve actuator 36 rests against stop 114 when the upper level of the fuel filling underground storage tank 94 is positioned below non-contact valve actuator 36. Upward travel of non-contact valve actuator 36 may similarly be limited by, e.g., stop 116 (FIG. 2 ). Stop 116 may also key non-contact valve actuator 36 to conduit wall exterior surface 30 to prohibit relative rotation between non-contact valve actuator 36 and conduit wall exterior surface 30.

Non-contact valve actuator 36 comprises a float having buoyancy characteristics such that it is buoyant on a surface of motor fuel. In one exemplary embodiment, float 36 has a specific gravity less than 0.7 so that it is buoyant on a surface of a quantity of motor fuel. As the liquid level in underground storage tank 94 rises, the top surface of fuel contained in underground storage tank 94 will encounter float 36. In one exemplary embodiment, when underground storage tank 94 achieves a liquid level corresponding to underground storage tank 94 being about 90% full, float 36 will travel upwardly until valve actuator magnet 42 is aligned with valve body magnet 44. Alternative configurations of the present disclosure will include valve actuators that actuate the primary valve at about 90%. This position of float 36 is illustrated in FIG. 5 , which also illustrates valve body magnet 44 moving from the at rest position illustrated in FIG. 4 to an actuated position, as illustrated in FIG. 5 . In this exemplary embodiment, valve actuator magnet 42 repels valve body magnet 44 to actuate valve body 34 from the open position illustrated in FIG. 4 toward the closed position illustrated in FIG. 6 . In the open position illustrated in FIG. 4 , valve body 34 is shielded from contact by fluid passing through conduit 22 by deflector 48. As illustrated in FIG. 3 , deflector 48 covers valve halves 108, 110 and arm 112 when valve body 34 maintains the open position illustrated in FIGS. 3 and 4 .

As float 36 rises and brings valve actuator magnet 42 into alignment with valve body magnet 44, valve body magnet 44 causes valve half 108 to rotate from the open position illustrated in FIG. 4 to an intermediate position as illustrated in FIG. 5 . In this position, flow F of fluid passing through conduit 22 can contact the upper surface of valve half 108. A portion of this flow is deflected from the upper surface of valve half 108 onto the upper surface of valve half 110. Flow F in the valve position illustrated in FIG. 5 causes valve halves 108 to move against the biasing force of the torsion spring acting to bias valve halves 108, 110 into the open position illustrated in FIG. 4 until valve halves 108, 110 achieve the closed position illustrated in FIG. 6 . As described above, when valve body 34 maintains the closed position illustrated in FIG. 6 , the maximum fill rate associated with underground storage tank 94 can no longer pass valve body 34. Further, the column of fluid maintained in the portion of drop tube 98 upstream from valve body 34 maintains valve body 34 in the closed position illustrated in FIG. 6 . If filling is halted, the column of fluid upstream of valve body 34 will eventually drain past valve body 34 in the leak position (described in greater detail below) and valve body 34 will be returned by the biasing force of the torsion spring to its at rest position, as illustrated, e.g., in FIG. 4 . As the volume of fuel contained in underground storage tank 94 continues to rise, as fluid passes valve body 34 in the leak position illustrated in FIG. 6 , float 36 will continue to rise until closure stop actuator magnet 38 aligns with closure stop magnet 46 as illustrated in FIG. 7 .

Closure stop 50, in the exemplary embodiment illustrated in FIGS. 2-7 , comprises a rotatable cam having cam extension 118 extending therefrom. With cam extension 118 positioned as illustrated in FIG. 6 , cam extension 118 prevents valve half 110 of valve body 34 from fully seating against its associated valve seat. As closure stop 50 is actuated from its at rest position as illustrated in FIG. 6 , it is moved out of contact with valve half 110 and the weight of the column of fuel positioned upstream of valve body 34 causes valve half 110 to fully seat against its associated valve seat, as illustrated in FIG. 7 . In this position, valve body 34 is designed to prevent flow through conduit 22. In one exemplary embodiment, float 36 will rise into the position causing actuation of closure stop 50 when underground storage tank is 95% full.

As fuel is drawn out of underground storage tank 94 by fuel dispenser 106, float 36 will return to a position in which it is no longer operable to actuate closure stop 50 and fluid will leak past valve body 34 until the column of fluid upstream of valve body 34 is depleted and valve body 34 returns to the normally biased position illustrated in FIG. 4 .

In the exemplary embodiment illustrated in FIG. 2-7 , closure stop actuator magnet 38 repels closure stop magnet 46 to cause actuation of closure stop 50. Closure stop 50 may be biased into the at rest position illustrated in FIGS. 4-5 by, e.g., gravity and/or a torsion spring. Magnets 38, 42, 44 and 46 may be any form of ferromagnetic material and/or any other item possessing magnetic qualities. Generally, “magnet” as used in this document is meant to denote any item having the ability to repel and/or attract another item through the use of a magnetic field.

While the embodiment illustrated in FIGS. 2-7 uses magnetic repulsion to actuate valve body 34 and closure stop 50, the present disclosure also contemplates use of magnetic attraction to actuate the valve body and closure stop. For example, FIG. 8 illustrates an alternative embodiment valve body 54 comprised of valve halves 120, 122, with arm 112 extending from valve half 122. In this embodiment, valve actuator magnet 42 and valve body magnet 44A are configured so that with valve actuator magnet 42 positioned proximate to valve body magnet 44 similar to the position of the previous embodiment illustrated in FIG. 5 , valve actuator magnet 42 will attract valve body magnet 44A and cause actuation of valve body 54 in a similar manner to that described above with respect to the embodiment illustrated in FIGS. 2-7 . In this embodiment, closure stop 50 is identical to the closure stop associated with the embodiment illustrated in FIGS. 2-7 and is not described in detail here for the sake of brevity.

FIGS. 9-13 illustrate an alternative embodiment overfill prevention valve in accordance with the present disclosure. Referring to FIG. 11 , valve body 74 is illustrated in a closed position, with poppet valve 52 (which will be described in further detail below) in an open position. In this configuration, a small amount of flow can pass valve body 74. When valve body 74 maintains the open position illustrated in FIG. 9 , conduit 62 is sufficiently open to allow passage of fuel at a normal fill rate. As described above, for applications in standard configurations, this fill rate is generally in the range of 300 to 500 gpm. In applications with remote filling capability, the standard flow rate may be as low as 25 gpm. With valve body 74 in the open position illustrated in FIG. 9 , the maximum fill rate is accommodated by conduit 62. In the closed position illustrated in FIG. 11 , and with poppet valve 52 open, the maximum fill rate is not allowed and, if filling at such a rate were to continue, the portion of drop tube 98 upstream of valve body 74 would fill with a column of fluid. The actuation mechanism which causes valve body 74 to move from the open position illustrated in FIG. 9 to the closed position illustrated in FIG. 11 (which will be described in more detail below) causes rapid closing of valve body 74, causing the fluid column upstream of valve body 34 to produce a line shock causing hose kick as described above.

With valve body 74 closed as illustrated in FIG. 11 , but with poppet valve 52 open, the column of fuel upstream of valve body 74 in drop tube 98 will slowly leak past valve body 74, allowing fill hose 104 to drain so that it can be properly disconnected from the fill port connected to underground storage tank 94. Valve body 74 is said to be in a “closed” position when it disallows passage of fluid at the maximum fill rate associated with underground storage tank 94. In this exemplary embodiment, the closed position is achieved when valve body 74 is fully seated against its associated valve seat. The closed condition of valve body 74 may be associated with an open condition of poppet valve 52 or a closed condition of poppet valve 52, the operation of which will be further described below.

Referring to FIG. 9 , valve body 74 is pivotally connected relative to drop tube segment 60. In an exemplary embodiment, valve body 74 may be pivotally connected by a rod connected to conduit wall interior surface 72. In the embodiment illustrated in FIGS. 9-14 , valve body 74 comprises a flapper valve. Flapper valve 74 can be biased into the open position illustrated in FIG. 9 , e.g., by a torsion spring. Secured to the body of flapper valve 74 is valve body magnet 44 b. With underground storage tank 94 filled to less than its capacity, tanker truck 102 can be utilized to provide additional motor fuel to underground storage tank 94 (FIG. 1 ). As underground storage tank 94 nears capacity, non-contact valve actuator 76 will actuate valve body 74 from the open position illustrated in FIG. 9 toward the closed position illustrated in FIG. 11 .

Similar to the embodiment illustrated in FIGS. 2-9 , drop tube segment 60 includes non-contact valve actuator 76 positioned about conduit wall exterior surface 70, with conduit wall 68 interposed between and physically separating non-contact valve actuator 76 from valve body 74. As described in detail below, non-contact valve actuator 76 is capable of actuating valve body 74 from the open position illustrated in FIG. 9 to a closed position such as the one illustrated in FIG. 11 , without physically penetrating conduit wall 68. Similar to non-contact valve actuator 36 described above, non-contact valve actuator 76 comprises a hollow cylinder sized to fit about and surround conduit wall exterior surface 70. Non-contact valve actuator 76 rests atop stop 126 when the upper level of the fuel filling underground storage tank 94 is positioned below non-contact valve actuator 76. Upward travel of non-contact valve actuator 76 may similarly be limited by, e.g., stop 124.

Similar to non-contact valve actuator 36, non-contact valve actuator 76 comprises a float having buoyancy characteristics such that it is buoyant on a surface of motor fuel. In one exemplary embodiment, float 36 has a specific gravity less than 0.7 so that it is buoyant on a surface of a quantity of motor fuel. As the liquid level in underground storage tank 94 rises, the top surface of fuel contained in underground storage tank 94 will encounter float 76. In one exemplary embodiment, when underground storage tank 94 achieves a liquid level corresponding to underground storage tank 94 being about 90% full, float 76 will travel upwardly until valve actuator magnet 42 b is aligned with valve body magnet 44 b. This position of float 36 is illustrated in FIG. 10 , which also illustrates valve body magnet 44 b moving from the at rest position illustrated in FIG. 9 to an actuated position as illustrated in FIG. 10 . In this exemplary embodiment, valve actuator magnet 42 b repels valve body magnet 44 b to actuate valve body 74 from the open position illustrated in FIG. 9 toward the closed position illustrated in FIG. 10 .

In the open position illustrated in FIG. 9 , valve body 74 is not susceptible to actuation from the open position illustrated in FIG. 9 toward the closed position illustrated in FIG. 10 by a flow of liquid traversing conduit 62. Valve body 74 is at least partially shielded from contact by fluid passing through conduit 62 by deflector 48 b. Deflector 48 b comprises a number of vanes oriented along the longitudinal axis of conduit 64 and further comprises a plate extending transverse the longitudinal axis of conduit 62 and positioned upstream of valve body 74 when valve body 74 maintains the open position illustrated in FIG. 9 . With valve body 74 is the open position illustrated in FIG. 9 , deflector 48 b shields valve body 74 from a flow of fluid through conduit 62. Deflector 48 b as well as deflector 48 described above, not only provide a shield to prevent a quantity of fluid flowing through the conduit from contacting the valve body, but also create an impediment to accidentally contacting the valve body with an implement such as a dipstick which may be inserted through drop tube 98 to determine the level of fluid in underground storage tank 94.

As float 76 rises and brings valve actuator magnet 42 b into alignment with valve body magnet 44 b, valve body magnet 44 b causes valve body 74 to rotate from the open position illustrated in FIG. 9 to an intermediate position as illustrated in FIG. 10 . In this position, flow F₁ of fluid passing through conduit 62 can contact the upper surface of valve body 74. Flow F₁ in the valve position illustrated in FIG. 10 causes valve body 74 to move against biasing force of torsion spring 128, which acts to bias valve body 74 into the open position illustrated in FIG. 9 , until valve body 74 achieves the closed position illustrated in FIG. 11 .

As described above, when valve body 74 maintains the closed position illustrated in FIG. 10 , the maximum fill rate associated with underground storage tank 94 can no longer pass valve body 74. Further, the column of fluid maintained in the portion of drop tube 98 upstream from valve body 74 maintains valve body 74 in the closed position illustrated in FIG. 6 . If filling is halted, the column of fluid upstream of valve body 74 will eventually drain past valve body 74 in the leak position and valve body 74 will be returned by the biasing force of torsion spring 128 to its at rest position, as illustrated, e.g., in FIG. 9 . As the volume of fuel contained in underground storage tank 94 continues to rise, as fluid passes valve body 74 in the leak position illustrated in FIG. 10 , float 36 will continue to rise until closure stop actuator magnet 38 b aligns with closure stop magnet 46 b as illustrated in FIG. 12 .

Closure stop 50 b, in the exemplary embodiment illustrated in FIGS. 9-13 , comprises a piston axially translatable relative to cylinder 130. Each of the piston and cylinder forming a part of closure stop 50 b may have opposing surfaces transverse to the axis along which the piston reciprocates relative to cylinder 130 and against which bears a compression spring to bias closure stop 50 b into the leak position illustrated in FIG. 11 . Closure stop 50 b includes cam extension 118 b extending therefrom. With cam extension 118 b positioned as illustrated in FIG. 11 , cam extension 118 pushes poppet valve 52 against the biasing force of spring 78 until poppet valve 52 is no longer seated against poppet valve seat 58 and poppet valve port 56 is placed in fluid communication with conduit 62. As closure stop 50 b is actuated from its at rest position illustrated in FIG. 9-11 , it is moved out of contact with poppet valve 52 and the weight of the column of fuel positioned upstream of valve body 74 together with the biasing force of spring 78 causes poppet valve 52 to fully seat against poppet valve seat 58 so that poppet valve port 56 is no longer in fluid communication with conduit 62. In this position, valve body 74 and poppet valve 52 are designed to prevent flow through conduit 22. In one exemplary embodiment, float 76 will rise into the position causing actuation of closure stop 50 b when underground storage tank is 95% full. As fuel is drawn out of underground storage tank 94 by fuel dispenser 106, float 76 will return to a position in which it is no longer operable to actuate closure stop 50 b and fluid will leak past valve body 74 until the column of fluid upstream of valve body 34 is depleted and valve body 34 returns to the normally biased position illustrated in FIG. 4 .

In the exemplary embodiment illustrated in FIGS. 9-13 , closure stop actuator magnet 38 b repels closure stop magnet 46 b to cause actuation of closure stop 50 b. Closure stop 50 b may, in alternative embodiments be actuated by an attractive force between closure stop actuator magnet 38 b and closure stop magnet 46 b. For example, an end of closure stop 50 b may be spaced from conduit wall interior surface 72, e.g., by a compression spring. In such an embodiment, a stop positioned outwardly from closure stop 50 b would prevent the aforementioned compression spring from extending the piston of closure stop 50 b more than a predetermined distance through cylinder 130. Specifically, the stop of this form of the present disclosure would prevent the piston of closure stop 50 b from extending further than a position in which cam extension 118 b is positioned to contact poppet valve 52. In such an embodiment, closure stop actuator magnet 38 b and closure stop magnet 46 b will be configured such that they will be attracted to each other so that positioning of closure stop actuator magnet 38 b in the position illustrated in FIG. 12 will cause closure stop magnet 46 b to be attracted toward closure stop actuator magnet 38 b against the biasing force of the aforementioned compression spring.

FIGS. 14-18 illustrate a further alternative embodiment overfill prevention valve in accordance with the present disclosure. Referring to FIG. 14 , drop tube segment 80 includes conduit 82 spanning first end 84 and second end 86 of conduit 82. Conduit wall 88 defines conduit wall interior surface 92 which defines a fluid path through conduit 82 from first end 84 to second end 86. Referring, e.g., to FIG. 15 , valve body 74 operates in identical fashion to valve body 74 illustrated above with respect to the embodiments shown in FIGS. 9-13 . Therefore, details concerning the operation of valve body 74 c will not be provided, for the sake of brevity.

As with the embodiment illustrated in FIGS. 9-13 , valve body 74 is movably positioned in the fluid path of conduit 82 and moveable from an open position to a closed position. Valve body 74 c is functionally identical to valve body 74, including the inclusion of a poppet valve and associated poppet valve port; however, non-contact valve actuator 96 (FIG. 14 ) is structurally and functionally different than the previously described non-contact valve actuators.

Referring to FIG. 14 , non-contact valve actuator 96 includes first float 132 and second float 134. First float 132 includes main body 136 defining shoulder 138. First float 132 includes guide channel 140 and guide rod apertures 142. Second float 134 includes main body 144, stop 146, guide extension 148, and guide rod apertures 150. Guide extension 148 is sized and shaped to fit within guide channel 140 of first float 132 such that guide channel 140 cooperates with guide extension 148 to guide relative movement of first float 132 and second float 134. In construction, second float 134 is positioned with guide extension 148 occupying guide channel 140. In this position, guide rod apertures 142 of first float 132 align with guide rod apertures 150 of second float 134. Guide rods 152 are then passed through guide rod apertures 150 of second float 134 and guide rod apertures 142 of first float 132 and are thereafter secured to guide rod retainers 154 of drop tube segment 80, with main body 136 of first float 132 occupying first float channel 156 and main body 144 of second float 134 positioned between guide rod retainers 154 and 154′. To complete securement of non-contact valve actuator 96 to drop tube segment 80, splash shield 158 is secured to drop tube segment 80 by, e.g. threaded fasteners. In its secured position, splash shield 158 retains guide rods 152 within guide rod retainers 154.

Referring to FIG. 15 , first float 132 maintains an at rest position with shoulder 138 of main body 136 abutting shoulder 160 formed in conduit wall exterior surface 90. As illustrated in FIG. 16 , upward travel of first float 132 is limited by shoulder 162 formed in conduit wall exterior surface 90. As illustrated in FIG. 17 , second float 134 maintains an at rest position in which main body 144 abuts guide rod retainers 154′. Upward travel of second float 134 can be limited by guide rod retainers 154. Referring to FIGS. 15 and 16 , first float 132 carries valve actuator magnet 42 c. Valve actuator magnet 42 c functions to actuate valve body 74 c in an identical fashion to the actuation of valve body 74 described above with reference to FIGS. 9 and 10 .

Unlike the previously described embodiments, first float 132 does not incorporate a closure stop actuator. In the embodiment illustrated in FIGS. 14-18 , the closure stop actuator takes the form of closure stop actuator magnet 38 c which is carried by second float 134. Second float 134 is actuatable independent of first float 132 and functions to actuate closure stop 50 c in the same fashion as described above with respect to closure stop 50 b (see FIGS. 11 and 12 ).

FIGS. 19-32 illustrate another embodiment of the present disclosure. Referring to FIGS. 19 and 20 , splash guard 158 d covers float 76 d and closure stop actuator magnet 38 d is secured in magnet holder 192 d. Guide rods 152 d are inserted through longitudinal apertures in float 76 d (covered from view in FIG. 19 ) so that float 76 can move along guide rods 152 d like the embodiment previously described and illustrated in FIGS. 14-18 . Referring to FIG. 21 , guide rods 152 d are inserted through apertures in magnet holder 192 to connect magnet holder 192 to drop pipe segment 60 d so that holder 192 can move along guide rods 152 d when ridge 198 of float 76 d rises to engage extension 196 to lift magnet holder 192.

Referring to FIG. 22 , flapper valve body 74 d (like flapper valve body 74 in FIG. 9 ) is illustrated in an open position to allow passage of fuel through valve body 74 at a normal flow rate, in the ranges previously described above. Referring to FIG. 28 , valve body 74 d (like flapper valve body 74 in FIG. 11 ) is illustrated in a closed position, and because poppet valve 52 d is in an open position, a small amount of fluid can still pass through valve body 74 d. Like previous embodiments, the initial transition of valve body 74 d from the open position illustrated in FIG. 22 to the closed position illustrated in FIG. 28 causes rapid closing of valve body 74 d because valve body 74 d is moved into the path of and is collided with the liquid stream flow.

Referring to FIG. 22 , valve body 74 d is pivotally connected to drop tube segment 60 d and, in an exemplary embodiment, may be pivotally connected by a rod connected to conduit wall interior surface 72 d. Valve body 74 d is biased in the open position by torsion spring 128 d, which has a lower spring constant than that disclosed in FIGS. 9-14 , and hold-open magnet 190 on float 76 d has an attractive force that also urges valve body 74 d into the open position when float 76 d maintains its lowered position, i.e., it has not yet begun to float on a quantity of product in underground storage tank 94. Specifically, hold-open magnet 190 and valve magnet 44 d are structured and arranged such that they have a magnetic attraction to each other. As storage tank 94 (shown in FIG. 1 ) nears capacity, float 76 d will rise to actuate valve body 74 d from the open position in FIG. 22 to the closed position illustrated in FIG. 28 .

Referring to FIGS. 19-32 , similar to first and second floats 132 and 132 in FIGS. 14-18 , guide rods 152 d are passed through guide rod slots 150 d to slidingly secure float 76 d to drop tube segment 60 d along conduit wall exterior surface 70 d and physically separated from valve body 74 d. Sharing the same buoyancy characteristics as non-contact valve actuator 36 in FIGS. 4-8 , in one exemplary embodiment, when the liquid level in underground storage tank 94 reaches about 90%, float 76 d will begin to rise to transition valve body 74 d from the open position in FIG. 22 to the closed position in FIG. 28 .

Before this transition, when valve body 74 d is in the open position, deflector 48 d shields valve body 74 d from being actuated by the flow of liquid through conduit 62 d. When the liquid level in storage tank 94 has buoyed float 76 d upward to actuate valve body 74 d to an intermediate position, out of the upright but not yet in the closed position, as illustrated in FIG. 26 , the flow of fluid through conduit 62 d begins to actuate valve body 74 d toward the closed position illustrated in FIG. 28 . Specifically, in FIG. 26 , the rising liquid level will urge float 76 d upward so that hold-open magnet 190 is no longer aligned with, and thus no longer attracts leftward (in the view of FIG. 26 ), valve magnet 44 d. Instead, repelling valve actuator magnet 42 d is moved into alignment with valve magnet 44 d to repel valve magnet 44 d and urge valve body 74 d to rotate downward, as shown by arrows A₁. Repelling valve actuator magnet 42 d and valve magnet 44 d are structured and arranged such that they magnetically repel one another. The repulsion of valve actuator magnet 42 d overcomes the bias of torsion spring 128 d to actuate valve body 74 d downward, on its way to achieving the closed position. Flow F₂, illustrated in FIG. 26 , urges valve body 74 d against the biasing force of the torsion spring 128 d as hold-open magnet 190 is no longer aligned with valve magnet 44 d to urge valve body 74 d to the open position. Once the valve body 74 d is in the closed position illustrated in FIG. 28 , fluid through conduit 62 d can no longer pass valve body 74 d at the maximum rate because valve body 74 d is in the leak position, as previously described.

Poppet valve 52 d, in the exemplary embodiment in FIGS. 19-32 , is substantially the same structure as poppet valve 52 b illustrated in FIGS. 9-13 . For example, referring specifically to FIG. 28 , like in previous embodiments, valve body 74 d is in the closed position, but poppet valve 52 d is open to allow a small amount of liquid to flow through valve body 74 d. However, fully seating poppet valve 52 d against poppet valve seat 58 d differs from the process previously described and illustrated in FIGS. 12 and 13 .

Referring back to FIG. 19 a , magnet holder 192 is illustrated holding closure stop actuator magnet 38 d and having a pair of arms 194 with extensions 196 extending from each arm 194. Each extension 196 is situated distance Di (FIG. 21 ) from ridge 198 formed along float 76 d. Referring now to FIG. 27 , magnet holder 192 has remained stationary while float 76 d has risen Di so that ridges 198 are adjacent extensions 196. At the same time, referring to FIG. 28 , closure stop 50 d includes cam extension 118 d that selectively pushes poppet valve 52 d upward and out of engagement with poppet valve seat 58 d. Closure stop actuator magnet 38 d and closure stop magnet 46 d share a magnetic attraction that urges closure stop magnet 46 d to the left (in the view illustrated in FIG. 28 ) against a closure stop spring (not shown) bias to engage cam extension 118 d with poppet valve 52 d, thereby creating the leak condition. Specifically, the closure stop spring (not shown) will bias closure stop 50 d into a position in which cam extension 118 d does not engage poppet valve 52 d; however, magnetic attraction shared by closure stop actuator magnet 38 d and closure stop magnet 46 d will overcome this spring bias to engage cam extension 118 d with poppet valve 52 d as illustrated in FIG. 28 .

Referring now to FIGS. 29 and 30 , float 76 d has risen so that ridges 198 have engaged extensions 196 to lift magnet holder 192. This lifting slides closure stop actuator magnet 38 d upward and out of alignment with closure stop magnet 46 d and consequently, closure stop 50 d shifts rightward due to the closure stop spring bias. Cam extension 118 d disengages poppet valve 52 d allowing poppet valve 52 d to fully seat against poppet valve seat 58 d. While the valve body of poppet valve 52 d is not illustrated in its seated position in FIG. 30 (FIG. 30 is meant to illustrate the initial movement of closure stop 50 d from the position illustrated in FIG. 28 ), poppet valve 52 d will return to a seated position such as the one illustrated in FIG. 32 just subsequent to movement of closure stop 50 d into the position illustrated in FIG. 30 .

As the fluid level in underground storage tank 94 lowers, closure stop actuator magnet 38 d is returned to the position illustrated in FIG. 28 to unseat poppet valve 52 d and allow flow at the previously mentioned leak flow rate. Prior to the unseating of poppet valve 52 d, fluid may pass valve body 74 at the “drain” rate described hereinabove. In any event, as conduit 62 d is cleared of the column of fluid that will accumulate when valve body 74 d maintains the closed position, torsion spring 128 d will return valve body 74 d to the fully opened position illustrated in FIG. 22 .

FIGS. 33-42 illustrate another embodiment of the present disclosure. Referring to FIG. 33 , float 76 e is illustrated in magnetic communication with shuttle 200 e. Float 76 e has a substantially equal buoyancy as floats in previous embodiments and is not in contact with shuttle 200 e, which is located interior of conduit wall interior surface 72 e (FIG. 34 ). Instead, in the present embodiment, float 76 e and shuttle 200 e each carry a pair of roller magnets 202 e and 204 e, respectively, which attract one another, so that as the liquid level in conduit 62 e

reaches a level at which float 76 e begins to rise, float 76 e will actuate the corresponding rise of shuttle 200 e. Roller magnets 202 e are cylindrical magnets having an opposite polarity to cylindrical roller magnets 204 e. Specifically, adjacent roller magnet pairs 202 e/204 e have opposite polarity. Further, roller magnets 202 e and 204 e are aligned with one another, i.e., they extend a similar distance both into and out of the section plane shown in FIG. 33 . As illustrated in FIG. 34 , roller magnets 202 e are positioned exterior of the conduit wall, i.e., exterior of conduit wall exterior surface 70 e. Similarly, roller magnets 204 e are positioned interior of the conduit wall, i.e., interior of conduit wall interior surface 72 e.

Referring to FIG. 34 , shuttle 200 e is illustrated with first flapper valve 206 e and second flapper valve 208 e biased upright in a fully open position. Torsion spring 128 e biases first flapper valve 206 e into the open position and upper latch 210 e of shuttle 200 e holds first flapper valve 206 e in the open position, as illustrated. First flapper valve 206 e has first roller 212 e extending through a yoke extending upwardly from flapper valve 206 e. First roller 212 e is engaged at a recess juxtaposed with upper latch 210 e, as illustrated in FIG. 4 , when first flapper valve 206 e maintains the closed position. In this position, second flapper valve 208 e is biased upright due to its planar engagement with first flapper valve 206 e. Further, second flapper valve 208 e includes upper magnet 216 e positioned through stem 218 e of second flapper valve 208 e. Magnet 220 e secured in valve base 222 e shares a magnetic attraction with upper magnet 216 e to urge second flapper valve 208 e into the fully opened position illustrated in FIG. 34 . Like first flapper valve 206 e, second flapper valve 208 e has a second roller 224 e extending between a yoke that projects from second flapper valve 208 e. Second roller 224 e occupies notch 226 e of shuttle 200 e in the fully opened position illustrated in FIG. 34 .

In the embodiment in FIGS. 33-43 , float 76 e begins to rise when the liquid level in tank 94 (shown in FIG. 1 ) reaches a sufficient height, as previously described for other embodiments. Roller magnets 202 e attract roller magnets 204 e so that float 76 e lifts shuttle 200 e, as float 76 e rises. Referring to FIGS. 34 and 35 , first and second flapper valves 206 e and 208 e are illustrated in the open position. Comparatively, referring to FIGS. 38 and 39 , when first flapper valve 206 e is in an intermediate position, between open and closed, the two pairs of roller magnets, 202 e and 204 e, have risen relative to first and second flapper valves 206 e and 208 e. This rising of both float 76 e and shuttle 200 e actuates the closing of both first and second flapper valves 206 e and 208 e, as described below.

Referring back to FIG. 34 , first and second flapper valves 206 e and 208 e are illustrated in the fully open position. As the liquid level in tank 94 (shown in FIG. 1 ) causes float 76 e to rise, shuttle 200 e will rise to actuate the closure of first and second flapper valves 206 e and 208 e. When this happens, both first and second rollers 212 e and 224 e ride along the vertical wall surfaces of shuttle 200 e. As float 76 e rises and, owing to the magnetic attraction between roller magnets 202 e and 204 e, shuttle 200 e rises, first roller 212 e and second roller 224 e will ride along upper ramp 228 e and the vertical wall forming lower notch 226 e, respectively, to attain the position illustrated in FIG. 37 . In this position, the magnetic attraction between upper magnet 216 e and magnet 220 e continues to hold second flapper valve 208 e in the fully opened position illustrated in FIG. 38 . In the position illustrated in FIG. 37 , the fluid flowing through the conduit will actuate first flapper valve 206 e into the closed position as described above with respect to various alternative flapper valve embodiments. With first flapper valve 206 e closed and second flapper valve 208 e still open, as illustrated in FIG. 38 , the leak position is achieved. As float 76 e continues to rise, second roller 224 e will ride along lower ramp 230 e until achieving the position illustrated in FIG. 39 . FIGS. 37 a and 38 a sequentially illustrate the change in position of float 76 e and shuttle 200 e to effect this movement.

As second flapper valve 208 e is forced by the interaction of second roller 224 e and lower ramp 230 e from the position illustrated in FIG. 38 to the position illustrated in FIG. 39 , the magnetic attraction between upper magnet 216 e and magnet 220 e is broken. With second flapper valve 208 e maintaining the position illustrated in FIG. 39 , the flow of fluid through the conduit will actuate second flapper valve 208 e into a closed position, as described above with respect to the various flapper valve embodiments of the present disclosure. With both first and second flapper valves 206 e and 208 e closed as illustrated in FIG. 40 , fluid may continue to flow through conduit 62 e at the drain flow rate described above, e.g., at 2% of maximum flow rate. As the column of fluid drains past first flapper valve 206 e and second flapper valve 208 e, torsion spring 128 e will return both first flapper valve 206 e and second flapper valve 208 e (owing to its seated position with respect to its valve seat, which is formed in first flapper valve 206 e) to the open position.

As the liquid level and flow decrease, float 76 e will descend and upward bias of torsion spring 128 e will begin to return both first and second flapper valves 206 e and 208 e to the open position. When this happens, referring from FIG. 41 to FIG. 42 , first and second rollers 212 e and 224 e will reengage upper and lower ramps 228 e and 230 e, respectively, and the lowering of shuttle 200 e and upward rolling of the rollers will reset the valves and shuttle 200 e to the open position illustrated in FIG. 35 . It is important to note that cam 232 e (which is rigidly secured to first flapper valve 206 e for rotation therewith) precludes shuttle 200 e from achieving its fully lowered position, as illustrated in FIG. 34 , unless first flapper valve 206 e is rotated to a position that is either fully open or nearly fully open. This is done so that shuttle 200 e cannot interfere with the opening of first flapper valve 206 e.

FIGS. 43-50 illustrate another embodiment of the present disclosure wherein the mechanism for actuating the closure of the two interior valves is float 76 f connected to a magnetic shaft coupling via link 303 f and lever arm 302 f. Once again, the two interior valves, first flapper valve 304 f and second flapper valve 306 f, each transition from an open to a closed position as the liquid level in tank 94 (shown in FIG. 1 ) rises past a certain threshold, as described for previous embodiments. However, this embodiment uses a rotational magnetic shaft coupling to transition first flapper valve 304 f and second flapper valve 306 f from open to closed positions. Specifically, referring to FIG. 44 , outer magnetic coupler 314 f is rotationally supported by a bearing on the exterior of conduit wall exterior surface 70 f, while inner magnetic coupler 316 f is rotationally supported by a bearing and supported on conduit wall interior surface 72 f Each of outer magnetic coupler 314 and inner magnetic coupler 316 include a plurality of bearings spaced about their perimeter, in the usual arrangement of a magnetic shaft coupler. The polarity of such magnets is configured such that movement of outer magnetic coupler 314 outside of fluid conduit 62 f yields corresponding rotational movement of inner magnetic coupler 316 f on the interior of conduit 62 f.

Referring to FIG. 44 , both first flapper valve 304 f and second flapper valve 306 f are illustrated in the open position. First flapper valve 304 f is biased in the upright position by torsion spring 128 f and held in this upright position by overhead latch 308 f. Second flapper valve 306 f is held in the upright position because it is in planar engagement with first flapper valve 304 f, making second flapper valve 306 f upright whenever first flapper valve 304 f is as well. Further, even without engagement by first flapper valve 304 f, second flapper valve 306 f would be held in place by the magnetic attraction between flapper valve magnet 312 f that is secured to pivot arm 322 f (as further described below) and magnet 313 f, which is secured to second flapper valve 306.

Referring to FIG. 45 , as the liquid level in tank 94 (shown in FIG. 1 ) reaches a certain level, float 76 f begins to rise, in the same way as described for previous embodiments. Also as previously described, deflector 48 f prevents liquid flow from urging either flapper valve downward until the given valve has been disengaged from the upright position. As float 76 f rises, link 303 f (FIG. 43 a ), which is pivotably connected both to float 76 f and to lever arm 302 f is pulled upward with float 76 f, thereby turning actuating outer magnetic coupler 314 f counterclockwise from the perspective illustrated in FIG. 43 a . This counterclockwise rotation acts on both first and second flapper valves 304 f and 306 f to transition each from an open to a closed position as described below.

Referring to FIGS. 45-47 , as float 76 f rotates outer magnetic coupler 314 f, inner magnetic coupler 316 f rotates as well. Inner magnetic coupler 316 f includes cammed surface 318 f that rotates to actuate overhead latch 308 f out of locking engagement with first flapper valve, as illustrated in FIG. 45 . As illustrated in FIG. 45 , latch 308 f is pivotally connected to conduit wall interior surface 72 f so that it will ride along cam surface 318 f and, from the perspective illustrated in FIG. 45 , rotate counterclockwise as it rides ever higher along the cammed surface 318 f of inner magnet coupler 316 f. In a position illustrated in FIG. 45 , overhead latch 308 no longer engages first flapper valve 304 f to hold it in the open position. Further, foot 309 f of overhead latch 308 forces first flapper valve 304 to rotate from its fully opened position. As rotation of inner magnet coupler 316 f continues, latch 308 f continues to be rotated counterclockwise to the further rotated position illustrated in FIG. 46 . In this position, foot 309 f sufficiently places first flapper valve 304 f in the fluid stream such that the fluid stream causes closing of first flapper valve 304 f as described above with respect to a variety of alternative embodiments. This position is illustrated in FIG. 47 . FIG. 47 a illustrates overhead latch 308 f in an open position, allowing first flapper valve 304 f to achieve the closed position, as previously described. In a position illustrated in FIG. 47 a , overhead latch 308 f has rotated the maximum amount provided by its interaction with cam surface 318 f. The position illustrated in FIG. 47 corresponds to the leak position. In this position, the closure stop (in the form of second flapper valve 306 f) maintains an open position such that first flapper valve 304 f maintains the “leak” condition.

From the position illustrated in FIGS. 47 and 47 a, when float 76 f continues to ascend, outer magnetic coupler 314 f is further rotated as link 303 f is pulled upwardly by float 76 f to rotate lever arm 302 f, causing corresponding rotation of inner magnetic coupler 316 f to the position illustrated in FIGS. 48 and 48 a. In this position, cam 320 f, which forms an integral part of inner magnetic coupler 316 f, actuates pivot arm 322 f, which carries second flapper valve magnet 312 f. Actuation of lever arm 322 f, as illustrated in FIG. 48 a breaks the magnetic attraction between second flapper valve magnet 312 f and magnet 313 f, which is secured to second flapper valve 306 f. In this position, there is no longer a magnetic attraction holding open second flapper valve 306 f. Therefore, second flapper valve 306 f begins to rotate into a closed position under its own weight, and the force of the fluid flowing through conduit 62 f. FIGS. 49 and 49 a further illustrate this configuration. With both first and second flapper valves 304 f and 306 f closed, as illustrated in FIGS. 49 and 49 a, fluid may continue to flow through conduit 62 f at the drain rate described above, e.g., at 2% of maximum flow rate. As the column of fluid drains past first flapper valve 304 f and second flapper valve 306 f, torsion spring 128 f will return both first flapper valve 304 f and second flapper valve 306 f (owing to a seated position with respect to its valve seat, which is formed in first flapper valve 304 f) to the open position.

As illustrated in FIG. 50 , as first flapper valve 304 f and second flapper valve 306 f are returned from a fully closed position illustrated in FIGS. 49 and 49 a to the fully opened position illustrated in FIG. 44 , first flapper valve 304 f contacts foot 309 f. If float 76 f has returned to its fully lowered position, as illustrated in FIG. 44 , then overhead latch 308 f will no longer be rotated outwardly as illustrated in FIG. 50 , but rather will maintain the position illustrated in FIG. 44 . In this position, ramped end 324 f of first flapper valve 304 can ride along the radiused outer profile of overhead latch 308 f to effect a minor counterclockwise rotation of latch 308 f (with respect to the perspective of FIG. 50 ), such that ramped end 324 f of first flapper valve 304 f can be secured by latch 308 f as illustrated in FIG. 44 . Details of the actuation mechanism described above can be found in FIGS. 51-56 . FIG. 52 illustrates inner magnet coupler 306 f in the same position illustrated in FIG. 44 . Alternative side elevational views of the construct in this position are also provided in FIGS. 51 and 53 . FIG. 54 provides a perspective view of inner magnetic coupler 316 f. Further, FIG. 55 provides a perspective view of overhead latch 308 f. Similarly, FIG. 56 provides a perspective view of pivot arm 322 f including pivot aperture 323 f and magnet holding aperture 325 f.

FIGS. 57-59 illustrate drop tube adaptor 400 secured to drop tube 402. Drop tube adaptor 400 may be threadedly engaged via female threads 406 to either end of any of the overfill prevention valves described in this document. Drop tube adapter 400 may further be secured to drop tube 402 via annular groove 414. Specifically, as illustrated in FIG. 58 , O-ring 416 is positioned within annular groove 414 (FIG. 57 ), and drop tube adaptor 400 is thereafter inserted into drop tube 402. In this position, drop tube 402 can be roll crimped to create exterior annular groove 410, as illustrated in FIG. 58 . Drop tube adaptor 400 further includes through bores 408, into which drop tube 402 can be deformed to form deformations 412 as illustrated in FIG. 58 . A fastener such as a rivet or bolt may then be used to further secure drop tube adaptor 400 to drive tube 402.

As described above, the overfill prevention valve in accordance with the present disclosure can include a valve actuator means for actuating a valve body from an open position to a closed position while the valve actuator means is positioned outside of the fluid path and without requiring a physical penetration of the wall defining the fluid path. Exemplary embodiments of the valve actuator means include the various float/magnet/actuator combinations described above.

Further, an overfill prevention valve in accordance with the present disclosure can include a leak means for selectively allowing a quantity of fluid to leak past a valve body when the valve body is in the closed position. Leak actuator means for actuating the leak means from a non-leak position in which the leak means does not allow the quantity of fluid to leak past the valve body to a leaked position in which the leak means allows the quantity of fluid to leak past the valve body include the various float/magnet/actuator combinations described above. The leak means may take the form of a closure stop which prevents full seating of the valve body in a closed position, as described above. The leak means may further take the form of a closure stop in the form of a secondary valve such as a poppet valve or a flapper valve which can be unseated when the primary valve maintains a closed position.

Any of the drop tube segments including an overfill prevention valve described above can be connected at their first and second ends to the remainder of drop tube 98 by a variety of connections including, e.g., threaded connections. Threaded adaptors may be utilized to effect such connections and o-rings may be provided to seal the drop tube segments of the present disclosure to the remainder of the drop tube.

While this disclosure has been described as having exemplary designs, the present disclosure can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains and which fall within the limits of the appended claims. 

What is claimed is:
 1. A system, comprising: an underground storage tank; a drop tube extending into said underground storage tank, said drop tube in fluid communication with said underground storage tank so that fluid passing through said drop tube fills said underground storage tank; and an overfill prevention valve forming a part of the drop tube, the overfill prevention valve comprising: a conduit having a first end and a second end, a conduit wall spanning said first end of said conduit and said second end of said conduit, said conduit wall defining a conduit wall interior surface and a conduit wall exterior surface, said conduit wall interior surface defining a fluid path through said conduit from said first end of said conduit to said second end of said conduit; a flapper valve hinged to the conduit, the flapper valve hingeable from an open position to a blocking position, the blocking position obstructing a flow though the conduit; a float moveable via buoyancy between a filling position corresponding to the open position of the valve body and an overfill-prevention position corresponding to the blocking position of the valve body; a float magnet associated with the float so that a float movement via buoyancy between the filling position and the overfill-prevention position yields a corresponding float magnet movement; and a valve magnet, the float magnet movement causing a valve magnet movement via a magnetic coupling of the valve magnet with the float magnet, the valve magnet movement triggering a flapper valve movement from the open position toward the blocking position.
 2. The system of claim 1, wherein the float magnet and the valve magnet together form a magnetic shaft coupling.
 3. An overfill prevention valve, comprising: a conduit having a first end and a second end, a conduit wall spanning said first end of said conduit and said second end of said conduit, said conduit wall defining a conduit wall interior surface and a conduit wall exterior surface, said conduit wall interior surface defining a fluid path through said conduit from said first end of said conduit to said second end of said conduit; a flapper valve hinged to the conduit, the flapper valve hingeable from an open position to a blocking position, the blocking position obstructing a flow though the conduit; a float moveable via buoyancy between a filling position corresponding to the open position of the valve body and an overfill-prevention position corresponding to the blocking position of the valve body; an outer magnetic coupler associated with the float so that a float movement via buoyancy between the filling position and the overfill-prevention position causes the outer magnetic coupler to rotate; and an inner magnetic coupler magnetically coupled to the outer magnetic coupler; wherein rotation of the outer magnetic coupler causes corresponding rotation of the inner magnetic coupler which causes movement of the flapper valve from the open position toward the blocking position.
 4. The overfill prevention valve of claim 3, further comprising a link pivotably connected to the float and to a lever arm connected to the outer magnetic coupler.
 5. The overfill prevention valve of claim 3, wherein the outer magnetic coupler is rotationally supported by a bearing on the conduit wall exterior surface and the inner magnetic coupler is rotationally supported by a bearing on the conduit wall interior surface.
 6. The overfill prevention valve of claim 3, wherein the inner magnetic coupler includes a cammed surface that rotates as the inner magnetic coupler rotates to actuate a latch our of locking engagement with the flapper valve. 